Choi Kyungho, Oshida Yoshiki, Platt Jeffrey A, Cochran Michael A, Matis Bruce A, Yi Keewook
Department of Mechanical Engineering, Syracuse University, Syracuse, Syracuse, NY, USA.
Oper Dent. 2006 Sep-Oct;31(5):590-7. doi: 10.2341/05-108.
In this laboratory study, the microtensile bond strengths of a conventional glass ionomer cement (GIC) and a resin modified glass ionomer cement (CRMGIC) to artificially created carious dentin and sound dentin were compared, and the ultrastructural morphology of the fractured interface was examined with a low-vacuum scanning electron microscope (SEM). The specimens were divided into 4 groups: 1) a conventional GIC (Ketac-Fil Plus Aplicap) placed on sound dentin; 2) a conventional GIC placed on artificially created carious dentin; 3) an RMGIC (Photac-Fil Aplicap) placed on sound dentin and 4) an RMGIC placed on artificially created carious dentin. Artificial carious lesions were created using a chemical demineralizing solution of 0.1 M/L lactic acid and 0.2% carbopol. GIC buildups were made on the dentin surfaces according to the manufacturer's directions. After storage in distilled water at 37 degrees C for 24 hours, the teeth were sectioned vertically into 1 x 1 x 8-mm beams for the microtensile bond strength test. The microtensile bond strength of each specimen was measured, and failure mode was determined using an optical microscope (40x). The fractured surfaces were further examined with SEM. Two-way analysis of variance showed that the mean microtensile bond strengths of a GIC and an RMGIC to carious dentin were significantly lower than those to sound dentin, and the mean microtensile bond strengths of Photac-Fil to both sound and carious dentin were significantly higher than those of Ketac-Fil Plus. Chi-square tests indicated that there was a significant difference in failure mode between the sound dentin and carious dentin groups. In sound dentin groups, cohesive failure in GIC was pre- dominant; whereas, mixed failure was predominant in carious dentin groups. SEM examination showed that the specimens determined to be cohesive failures under light microscopy in the Photac-Fil/Sound Dentin group were actually mixed failures under high magnification of SEM.
在这项实验室研究中，比较了传统玻璃离子水门汀（GIC）和树脂改性玻璃离子水门汀（CRMGIC）与人工制备的龋损牙本质和健康牙本质之间的微拉伸粘结强度，并用低真空扫描电子显微镜（SEM）检查了断裂界面的超微结构形态。标本分为4组：1）将传统GIC（Ketac-Fil Plus Aplicap）置于健康牙本质上；2）将传统GIC置于人工制备的龋损牙本质上；3）将树脂改性玻璃离子水门汀（Photac-Fil Aplicap）置于健康牙本质上；4）将树脂改性玻璃离子水门汀置于人工制备的龋损牙本质上。使用0.1M/L乳酸和0.2%卡波姆的化学脱矿溶液制备人工龋损。按照制造商的说明在牙本质表面进行GIC修复。在37℃蒸馏水中储存24小时后，将牙齿垂直切成1×1×8mm的梁进行微拉伸粘结强度测试。测量每个标本的微拉伸粘结强度，并使用光学显微镜（40倍）确定失效模式。用SEM进一步检查断裂表面。双向方差分析表明，GIC和树脂改性玻璃离子水门汀与龋损牙本质之间的平均微拉伸粘结强度显著低于与健康牙本质之间的平均微拉伸粘结强度，并且Photac-Fil与健康牙本质和龋损牙本质之间的平均微拉伸粘结强度均显著高于Ketac-Fil Plus。卡方检验表明，健康牙本质组和龋损牙本质组之间的失效模式存在显著差异。在健康牙本质组中，GIC内聚性失效占主导；而在龋损牙本质组中，混合性失效占主导。SEM检查显示，在光学显微镜下确定为Photac-Fil/健康牙本质组内聚性失效的标本在SEM高倍放大下实际上是混合性失效。
